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| author | Josh Wu <josh.wu@atmel.com> | 2013-08-05 19:14:37 +0800 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2013-08-05 21:07:51 +0100 |
| commit | 6054d4d56307839bffabb687767c24d5ff62563b (patch) | |
| tree | cb34b9efc666b617894df1722ae03b60e20587da /Documentation | |
| parent | 1ae9c092efcca18876921548b2d16cf7c4b53fda (diff) | |
| download | linux-6054d4d56307839bffabb687767c24d5ff62563b.tar.gz linux-6054d4d56307839bffabb687767c24d5ff62563b.tar.bz2 linux-6054d4d56307839bffabb687767c24d5ff62563b.zip | |
mtd: atmel_nand: enable Nand Flash Controller (NFC) write via sram
This patch enable writing nand flash via NFC SRAM. It will minimize the CPU
overhead. The SRAM write only support ECC_NONE and ECC_HW with PMECC.
To enable this NFC write by SRAM feature, you can add a string in dts under
NFC driver node.
This driver has been tested on SAMA5D3X-EK with JFFS2, YAFFS2, UBIFS and
mtd-utils.
Here is part of mtd_speedtest (writing test) result, compare with non-NFC
writing, it reduces %65 cpu load with loss %12 speed.
- commands use to test:
# insmod /mnt/mtd_speedtest.ko dev=2 &
# top -n 30 -d 1 | grep speedtest
- test result:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
mtd_speedtest: testing eraseblock write speed
509 495 root D 1164 0% 7% insmod /mnt/mtd_speedtest.ko dev=2
509 495 root D 1164 0% 8% insmod /mnt/mtd_speedtest.ko dev=2
509 495 root R 1164 0% 5% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock write speed is 5194 KiB/s
mtd_speedtest: testing page write speed
509 495 root D 1164 0% 32% insmod /mnt/mtd_speedtest.ko dev=2
509 495 root D 1164 0% 27% insmod /mnt/mtd_speedtest.ko dev=2
509 495 root D 1164 0% 25% insmod /mnt/mtd_speedtest.ko dev=2
509 495 root D 1164 0% 30% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page write speed is 5024 KiB/s
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/mtd/atmel-nand.txt | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt index 5d8b7d5c914d..c4728839d0c1 100644 --- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt @@ -36,6 +36,8 @@ Optional properties: - reg : should specify the address and size used for NFC command registers, NFC registers and NFC Sram. NFC Sram address and size can be absent if don't want to use it. + - Optional properties: + - atmel,write-by-sram: boolean to enable NFC write by sram. Examples: nand0: nand@40000000,0 { |